Yes they are awesome (best ones are the first and the jungle series big ones, golden city never did it for me, although the Aero Booster is awesome), an nowadays bricklink is your best option on getting some.

The first series was amazing, I owned all of the first bunch (not sets, but all the mechs)
The second was nice, the third was OK, the fourth I ignored and decided that the first and second where the only ones that existed and that the battle never left the bridge.